Conventionally, in order to perform a stable puncture and reduce the pain caused by the puncture, a coating agent, such as silicone resin, fluorine resin or the like, is coated onto the surface of a needle tip of a needle tube. Further, by coating the coating agent onto the surface of the needle tip, the roughness of the tip-end portion of the needle tube is reduced. Therefore, it is possible to reduce the friction between the skin and the needle tube caused in use, reduce the pain caused by the puncture, and perform a stable puncture to the skin.
For example, Patent document 1 describes an art in which a quartz film, which is chemically neutral and stable, is used as the coating agent applied to the surface of the needle tip of the needle tube.